Magnetic card readers, such as those described in U.S. Pat. No. 4,476,507, include feed rollers for driving identification cards wherein the rollers have a transverse axis of symmetry, i.e., symmetrical to the width of the card. The transverse axis of symmetry differs from the axis of symmetry of a head for reading data from the card. As a result, the card is fed asymmetrically, whereby the card tends to rotate inside of a guide therefor, to generate friction. To compensate for the friction the card is continuously held against a reference surface of a card guiding system. This structure introduces additional friction, resulting in card wear and requiring increased roller contact pressure on the card which also causes wear on the card.
U.S. Pat. No. 3,836,753 and European Patent Application No. 0,125,655 disclose card readers that compensate for differences in card thickness without affecting how accurately a magnetic track is read. Generally, these devices include a bracket supporting a magnetic head that is held against the card with a constant pressure by an elastic means for exerting tension against the card. To ensure that the data on the magnetic track of the card, even a deformed card, are read accurately by these devices, the contact pressure of the head on the card is increased. As a result the card wears more rapidly and there is faster deterioration of the magnetic track and read head.